You don't need Kafka: Building a message queue with Unix signals
2 days ago
- #IPC
- #Ruby
- #UNIX
- The article explores building a simple message queue using only two UNIX signals (SIGUSR1 and SIGUSR2) for inter-process communication (IPC).
- UNIX signals are standardized messages that trigger specific behaviors in processes, with SIGUSR1 and SIGUSR2 being user-defined signals ideal for custom purposes.
- The author demonstrates encoding and decoding messages by representing binary bits (0 and 1) with SIGUSR1 and SIGUSR2, respectively.
- A receiver process accumulates bits from signals, decodes them into bytes, and converts them back to ASCII characters.
- A sender process encodes a message into binary bits and sends them as signals to the receiver.
- The implementation includes handling NULL terminators (00000000) to mark the end of a message.
- The article extends the concept to a modest message broker with producers, consumers, and a broker routing messages via signals.
- The SignalCodec module encapsulates the logic for encoding/decoding messages and performing bitwise operations.
- The project is experimental and not production-ready but serves as a fun exploration of low-level programming concepts.
- Key takeaways include understanding binary operations, UNIX signals, IPC, and the joy of building 'useless' but educational projects.